System and method for vehicle occlusion detection

ABSTRACT

A system and method for vehicle occlusion detection is disclosed. A particular embodiment includes: receiving training image data from a training image data collection system; obtaining ground truth data corresponding to the training image data; performing a training phase to train a plurality of classifiers, a first classifier being trained for processing static images of the training image data, a second classifier being trained for processing image sequences of the training image data; receiving image data from an image data collection system associated with an autonomous vehicle; and performing an operational phase including performing feature extraction on the image data, determining a presence of an extracted feature instance in multiple image frames of the image data by tracing the extracted feature instance back to a previous plurality of N frames relative to a current frame, applying the first trained classifier to the extracted feature instance if the extracted feature instance cannot be determined to be present in multiple image frames of the image data, and applying the second trained classifier to the extracted feature instance if the extracted feature instance can be determined to be present in multiple image frames of the image data.

PRIORITY PATENT APPLICATIONS

This is a continuation patent application drawing priority from U.S. non-provisional patent application Ser. No. 15/796,769; filed Oct. 28, 2017; which is a continuation-in-part (CIP) patent application drawing priority from U.S. non-provisional patent application Ser. No. 15/693,446; filed Aug. 31, 2017. This present non-provisional CIP patent application draws priority from the referenced patent applications. The entire disclosure of the referenced patent applications is considered part of the disclosure of the present application and is hereby incorporated by reference herein in its entirety.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. The following notice applies to the disclosure herein and to the drawings that form a part of this document: Copyright 2016-2019, TuSimple, All Rights Reserved.

TECHNICAL FIELD

This patent document pertains generally to tools (systems, apparatuses, methodologies, computer program products, etc.) for image processing, vehicle control systems, and autonomous driving systems, and more particularly, but not by way of limitation, to a system and method for vehicle occlusion detection.

BACKGROUND

Object contour and occlusion detection is a fundamental problem for numerous vision tasks, including image segmentation, object detection, semantic instance segmentation, and occlusion reasoning. Detecting all objects in a traffic environment, such as cars, buses, pedestrians, and bicycles, is crucial for building an autonomous driving system. Failure to detect an object (e.g., a car or a person) may lead to malfunction of the motion planning module of an autonomous driving car, thus resulting in a catastrophic accident. As such, object occlusion detection for autonomous vehicles is an important safety issue.

There are various states of occlusion. Identifying specific types of occlusion can facilitate the process of object occlusion detection for autonomous vehicles. The most common types of object occlusion are: one object occluding another object, one object is occluded by another object, one object is between two other objects, and an object is separated from other objects. For autonomous vehicle occlusion detection, the major types of objects that need to be detected are cars, motorcycles, bicycles, persons, and the like. Accurately distinguishing the relationship among objects around a host autonomous vehicle provides valuable information for motion planning, driving inference generation, and other processes of the autonomous vehicle operation.

Object contour and occlusion detection can involve the use of semantic segmentation. Semantic segmentation aims to assign a categorical label to every pixel in an image, which plays an important role in image analysis and self-driving systems. The semantic segmentation framework provides pixel-level categorical labeling, but no single object-level instance can be discovered. Current object detection frameworks, although useful, cannot recover the shape of the object or deal with the occluded object detection problem. A more accurate and efficient detection of object occlusion is needed for autonomous vehicle operation.

SUMMARY

A system and method for vehicle occlusion detection is disclosed. The example system and method for detecting vehicle occlusion includes an offline (training) model to receive images from a camera configured on a host vehicle; generate ground truth information; train a first classifier with extracted X features for each vehicle object; track all detected vehicle objects, and train a second classifier with extracted X*N features for each vehicle object. The system and method of an example embodiment further includes an operational (non-training) model to track all detected vehicle objects to determine whether each vehicle object can be tracked back to a previous N frames or not; extract X types of features for those vehicle objects that cannot be tracked back and test with a first trained classifier; and extract X*N types of features for those vehicle objects that can be tracked back and test with a second trained classifier.

BRIEF DESCRIPTION OF THE DRAWINGS

The various embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which:

FIG. 1 illustrates a block diagram of an example ecosystem in which an in-vehicle image processing module of an example embodiment can be implemented;

FIG. 2 illustrates the offline training phase (a first phase) used to configure or train the autonomous vehicle occlusion detection system, and the classifiers therein, in an example embodiment;

FIG. 3 illustrates a sample static image that may be used by an example embodiment to train the first classifier to process a static image;

FIG. 4 illustrates a sample image sequence that may be used by an example embodiment to train the second classifier to process image sequences;

FIG. 5 illustrates an operational flow diagram showing a process used in an example embodiment to train the first classifier to generate occlusion status for vehicle objects in a static input image;

FIG. 6 illustrates an operational flow diagram showing a process used in an example embodiment to train the second classifier to generate occlusion status for vehicle objects detected in image sequences;

FIG. 7 illustrates a second phase for operational or simulation use of the autonomous vehicle occlusion detection system in an example embodiment;

FIG. 8 illustrates a detail of the second phase for operational or simulation use of the autonomous vehicle occlusion detection system in an example embodiment;

FIGS. 9 through 12 illustrate a set of sample images that highlight the basic operations performed in an example embodiment;

FIG. 13 is a process flow diagram illustrating an example embodiment of a system and method for vehicle occlusion detection; and

FIG. 14 shows a diagrammatic representation of machine in the example form of a computer system within which a set of instructions when executed may cause the machine to perform any one or more of the methodologies discussed herein.

DETAILED DESCRIPTION

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the various embodiments. It will be evident, however, to one of ordinary skill in the art that the various embodiments may be practiced without these specific details.

As described in various example embodiments, a system and method for vehicle occlusion detection are described herein. An example embodiment disclosed herein can be used in the context of an in-vehicle control system 150 in a vehicle ecosystem 101. In one example embodiment, an in-vehicle control system 150 with an image processing module 200 resident in a vehicle 105 can be configured like the architecture and ecosystem 101 illustrated in FIG. 1. However, it will be apparent to those of ordinary skill in the art that the image processing module 200 described and claimed herein can be implemented, configured, and used in a variety of other applications and systems as well.

Referring now to FIG. 1, a block diagram illustrates an example ecosystem 101 in which an in-vehicle control system 150 and an image processing module 200 of an example embodiment can be implemented. These components are described in more detail below. Ecosystem 101 includes a variety of systems and components that can generate and/or deliver one or more sources of information/data and related services to the in-vehicle control system 150 and the image processing module 200, which can be installed in the vehicle 105. For example, a camera installed in the vehicle 105, as one of the devices of vehicle subsystems 140, can generate image and timing data that can be received by the in-vehicle control system 150. The in-vehicle control system 150 and the image processing module 200 executing therein can receive this image and timing data input. As described in more detail below, the image processing module 200 can process the image input and extract object features, which can be used by an autonomous vehicle control subsystem, as another one of the subsystems of vehicle subsystems 140. The autonomous vehicle control subsystem, for example, can use the real-time extracted object features to safely and efficiently navigate and control the vehicle 105 through a real world driving environment while avoiding obstacles and safely controlling the vehicle.

In an example embodiment as described herein, the in-vehicle control system 150 can be in data communication with a plurality of vehicle subsystems 140, all of which can be resident in a user's vehicle 105. A vehicle subsystem interface 141 is provided to facilitate data communication between the in-vehicle control system 150 and the plurality of vehicle subsystems 140. The in-vehicle control system 150 can be configured to include a data processor 171 to execute the image processing module 200 for processing image data received from one or more of the vehicle subsystems 140. The data processor 171 can be combined with a data storage device 172 as part of a computing system 170 in the in-vehicle control system 150. The data storage device 172 can be used to store data, processing parameters, and data processing instructions. A processing module interface 165 can be provided to facilitate data communications between the data processor 171 and the image processing module 200. In various example embodiments, a plurality of processing modules, configured similarly to image processing module 200, can be provided for execution by data processor 171. As shown by the dashed lines in FIG. 1, the image processing module 200 can be integrated into the in-vehicle control system 150, optionally downloaded to the in-vehicle control system 150, or deployed separately from the in-vehicle control system 150.

The in-vehicle control system 150 can be configured to receive or transmit data from/to a wide-area network 120 and network resources 122 connected thereto. An in-vehicle web-enabled device 130 and/or a user mobile device 132 can be used to communicate via network 120. A web-enabled device interface 131 can be used by the in-vehicle control system 150 to facilitate data communication between the in-vehicle control system 150 and the network 120 via the in-vehicle web-enabled device 130. Similarly, a user mobile device interface 133 can be used by the in-vehicle control system 150 to facilitate data communication between the in-vehicle control system 150 and the network 120 via the user mobile device 132. In this manner, the in-vehicle control system 150 can obtain real-time access to network resources 122 via network 120. The network resources 122 can be used to obtain processing modules for execution by data processor 171, data content to train internal neural networks, system parameters, or other data.

The ecosystem 101 can include a wide area data network 120. The network 120 represents one or more conventional wide area data networks, such as the Internet, a cellular telephone network, satellite network, pager network, a wireless broadcast network, gaming network, WiFi network, peer-to-peer network, Voice over IP (VoIP) network, etc. One or more of these networks 120 can be used to connect a user or client system with network resources 122, such as websites, servers, central control sites, or the like. The network resources 122 can generate and/or distribute data, which can be received in vehicle 105 via in-vehicle web-enabled devices 130 or user mobile devices 132. The network resources 122 can also host network cloud services, which can support the functionality used to compute or assist in processing image input or image input analysis. Antennas can serve to connect the in-vehicle control system 150 and the image processing module 200 with the data network 120 via cellular, satellite, radio, or other conventional signal reception mechanisms. Such cellular data networks are currently available (e.g., Verizon™, AT&T™, T-Mobile™, etc.). Such satellite-based data or content networks are also currently available (e.g., SiriusXM™, HughesNet™, etc.). The conventional broadcast networks, such as AM/FM radio networks, pager networks, UHF networks, gaming networks, WiFi networks, peer-to-peer networks, Voice over IP (VoIP) networks, and the like are also well-known. Thus, as described in more detail below, the in-vehicle control system 150 and the image processing module 200 can receive web-based data or content via an in-vehicle web-enabled device interface 131, which can be used to connect with the in-vehicle web-enabled device receiver 130 and network 120. In this manner, the in-vehicle control system 150 and the image processing module 200 can support a variety of network-connectable in-vehicle devices and systems from within a vehicle 105.

As shown in FIG. 1, the in-vehicle control system 150 and the image processing module 200 can also receive data, image processing control parameters, and training content from user mobile devices 132, which can be located inside or proximately to the vehicle 105. The user mobile devices 132 can represent standard mobile devices, such as cellular phones, smartphones, personal digital assistants (PDA's), MP3 players, tablet computing devices (e.g., iPad™), laptop computers, CD players, and other mobile devices, which can produce, receive, and/or deliver data, image processing control parameters, and content for the in-vehicle control system 150 and the image processing module 200. As shown in FIG. 1, the mobile devices 132 can also be in data communication with the network cloud 120. The mobile devices 132 can source data and content from internal memory components of the mobile devices 132 themselves or from network resources 122 via network 120. Additionally, mobile devices 132 can themselves include a GPS data receiver, accelerometers, WiFi triangulation, or other geo-location sensors or components in the mobile device, which can be used to determine the real-time geo-location of the user (via the mobile device) at any moment in time. In any case, the in-vehicle control system 150 and the image processing module 200 can receive data from the mobile devices 132 as shown in FIG. 1.

Referring still to FIG. 1, the example embodiment of ecosystem 101 can include vehicle operational subsystems 140. For embodiments that are implemented in a vehicle 105, many standard vehicles include operational subsystems, such as electronic control units (ECUs), supporting monitoring/control subsystems for the engine, brakes, transmission, electrical system, emissions system, interior environment, and the like. For example, data signals communicated from the vehicle operational subsystems 140 (e.g., ECUs of the vehicle 105) to the in-vehicle control system 150 via vehicle subsystem interface 141 may include information about the state of one or more of the components or subsystems of the vehicle 105. In particular, the data signals, which can be communicated from the vehicle operational subsystems 140 to a Controller Area Network (CAN) bus of the vehicle 105, can be received and processed by the in-vehicle control system 150 via vehicle subsystem interface 141. Embodiments of the systems and methods described herein can be used with substantially any mechanized system that uses a CAN bus or similar data communications bus as defined herein, including, but not limited to, industrial equipment, boats, trucks, machinery, or automobiles; thus, the term “vehicle” as used herein can include any such mechanized systems. Embodiments of the systems and methods described herein can also be used with any systems employing some form of network data communications; however, such network communications are not required.

Referring still to FIG. 1, the example embodiment of ecosystem 101, and the vehicle operational subsystems 140 therein, can include a variety of vehicle subsystems in support of the operation of vehicle 105. In general, the vehicle 105 may take the form of a car, truck, motorcycle, bus, boat, airplane, helicopter, lawn mower, earth mover, snowmobile, aircraft, recreational vehicle, amusement park vehicle, farm equipment, construction equipment, tram, golf cart, train, and trolley, for example. Other vehicles are possible as well. The vehicle 105 may be configured to operate fully or partially in an autonomous mode. For example, the vehicle 105 may control itself while in the autonomous mode, and may be operable to determine a current state of the vehicle and its environment, determine a predicted behavior of at least one other vehicle in the environment, determine a confidence level that may correspond to a likelihood of the at least one other vehicle to perform the predicted behavior, and control the vehicle 105 based on the determined information. While in autonomous mode, the vehicle 105 may be configured to operate without human interaction.

The vehicle 105 may include various vehicle subsystems such as a vehicle drive subsystem 142, vehicle sensor subsystem 144, vehicle control subsystem 146, and occupant interface subsystem 148. As described above, the vehicle 105 may also include the in-vehicle control system 150, the computing system 170, and the image processing module 200. The vehicle 105 may include more or fewer subsystems and each subsystem could include multiple elements. Further, each of the subsystems and elements of vehicle 105 could be interconnected. Thus, one or more of the described functions of the vehicle 105 may be divided up into additional functional or physical components or combined into fewer functional or physical components. In some further examples, additional functional and physical components may be added to the examples illustrated by FIG. 1.

The vehicle drive subsystem 142 may include components operable to provide powered motion for the vehicle 105. In an example embodiment, the vehicle drive subsystem 142 may include an engine or motor, wheels/tires, a transmission, an electrical subsystem, and a power source. The engine or motor may be any combination of an internal combustion engine, an electric motor, steam engine, fuel cell engine, propane engine, or other types of engines or motors. In some example embodiments, the engine may be configured to convert a power source into mechanical energy. In some example embodiments, the vehicle drive subsystem 142 may include multiple types of engines or motors. For instance, a gas-electric hybrid car could include a gasoline engine and an electric motor. Other examples are possible.

The wheels of the vehicle 105 may be standard tires. The wheels of the vehicle 105 may be configured in various formats, including a unicycle, bicycle, tricycle, or a four-wheel format, such as on a car or a truck, for example. Other wheel geometries are possible, such as those including six or more wheels. Any combination of the wheels of vehicle 105 may be operable to rotate differentially with respect to other wheels. The wheels may represent at least one wheel that is fixedly attached to the transmission and at least one tire coupled to a rim of the wheel that could make contact with the driving surface. The wheels may include a combination of metal and rubber, or another combination of materials. The transmission may include elements that are operable to transmit mechanical power from the engine to the wheels. For this purpose, the transmission could include a gearbox, a clutch, a differential, and drive shafts. The transmission may include other elements as well. The drive shafts may include one or more axles that could be coupled to one or more wheels. The electrical system may include elements that are operable to transfer and control electrical signals in the vehicle 105. These electrical signals can be used to activate lights, servos, electrical motors, and other electrically driven or controlled devices of the vehicle 105. The power source may represent a source of energy that may, in full or in part, power the engine or motor. That is, the engine or motor could be configured to convert the power source into mechanical energy. Examples of power sources include gasoline, diesel, other petroleum-based fuels, propane, other compressed gas-based fuels, ethanol, fuel cell, solar panels, batteries, and other sources of electrical power. The power source could additionally or alternatively include any combination of fuel tanks, batteries, capacitors, or flywheels. The power source may also provide energy for other subsystems of the vehicle 105.

The vehicle sensor subsystem 144 may include a number of sensors configured to sense information about an environment or condition of the vehicle 105. For example, the vehicle sensor subsystem 144 may include an inertial measurement unit (IMU), a Global Positioning System (GPS) transceiver, a RADAR unit, a laser range finder/LIDAR unit, and one or more cameras or image capture devices. The vehicle sensor subsystem 144 may also include sensors configured to monitor internal systems of the vehicle 105 (e.g., an O2 monitor, a fuel gauge, an engine oil temperature). Other sensors are possible as well. One or more of the sensors included in the vehicle sensor subsystem 144 may be configured to be actuated separately or collectively in order to modify a position, an orientation, or both, of the one or more sensors.

The IMU may include any combination of sensors (e.g., accelerometers and gyroscopes) configured to sense position and orientation changes of the vehicle 105 based on inertial acceleration. The GPS transceiver may be any sensor configured to estimate a geographic location of the vehicle 105. For this purpose, the GPS transceiver may include a receiver/transmitter operable to provide information regarding the position of the vehicle 105 with respect to the Earth. The RADAR unit may represent a system that utilizes radio signals to sense objects within the local environment of the vehicle 105. In some embodiments, in addition to sensing the objects, the RADAR unit may additionally be configured to sense the speed and the heading of the objects proximate to the vehicle 105. The laser range finder or LIDAR unit may be any sensor configured to sense objects in the environment in which the vehicle 105 is located using lasers. In an example embodiment, the laser range finder/LIDAR unit may include one or more laser sources, a laser scanner, and one or more detectors, among other system components. The laser range finder/LIDAR unit could be configured to operate in a coherent (e.g., using heterodyne detection) or an incoherent detection mode. The cameras may include one or more devices configured to capture a plurality of images of the environment of the vehicle 105. The cameras may be still image cameras or motion video cameras.

The vehicle control system 146 may be configured to control operation of the vehicle 105 and its components. Accordingly, the vehicle control system 146 may include various elements such as a steering unit, a throttle, a brake unit, a navigation unit, and an autonomous control unit.

The steering unit may represent any combination of mechanisms that may be operable to adjust the heading of vehicle 105. The throttle may be configured to control, for instance, the operating speed of the engine and, in turn, control the speed of the vehicle 105. The brake unit can include any combination of mechanisms configured to decelerate the vehicle 105. The brake unit can use friction to slow the wheels in a standard manner. In other embodiments, the brake unit may convert the kinetic energy of the wheels to electric current. The brake unit may take other forms as well. The navigation unit may be any system configured to determine a driving path or route for the vehicle 105. The navigation unit may additionally be configured to update the driving path dynamically while the vehicle 105 is in operation. In some embodiments, the navigation unit may be configured to incorporate data from the image processing module 200, the GPS transceiver, and one or more predetermined maps so as to determine the driving path for the vehicle 105. The autonomous control unit may represent a control system configured to identify, evaluate, and avoid or otherwise negotiate potential obstacles in the environment of the vehicle 105. In general, the autonomous control unit may be configured to control the vehicle 105 for operation without a driver or to provide driver assistance in controlling the vehicle 105. In some embodiments, the autonomous control unit may be configured to incorporate data from the image processing module 200, the GPS transceiver, the RADAR, the LIDAR, the cameras, and other vehicle subsystems to determine the driving path or trajectory for the vehicle 105. The vehicle control system 146 may additionally or alternatively include components other than those shown and described.

Occupant interface subsystems 148 may be configured to allow interaction between the vehicle 105 and external sensors, other vehicles, other computer systems, and/or an occupant or user of vehicle 105. For example, the occupant interface subsystems 148 may include standard visual display devices (e.g., plasma displays, liquid crystal displays (LCDs), touchscreen displays, heads-up displays, or the like), speakers or other audio output devices, microphones or other audio input devices, navigation interfaces, and interfaces for controlling the internal environment (e.g., temperature, fan, etc.) of the vehicle 105.

In an example embodiment, the occupant interface subsystems 148 may provide, for instance, means for a user/occupant of the vehicle 105 to interact with the other vehicle subsystems. The visual display devices may provide information to a user of the vehicle 105. The user interface devices can also be operable to accept input from the user via a touchscreen. The touchscreen may be configured to sense at least one of a position and a movement of a user's finger via capacitive sensing, resistance sensing, or a surface acoustic wave process, among other possibilities. The touchscreen may be capable of sensing finger movement in a direction parallel or planar to the touchscreen surface, in a direction normal to the touchscreen surface, or both, and may also be capable of sensing a level of pressure applied to the touchscreen surface. The touchscreen may be formed of one or more translucent or transparent insulating layers and one or more translucent or transparent conducting layers. The touchscreen may take other forms as well.

In other instances, the occupant interface subsystems 148 may provide means for the vehicle 105 to communicate with devices within its environment. The microphone may be configured to receive audio (e.g., a voice command or other audio input) from a user of the vehicle 105. Similarly, the speakers may be configured to output audio to a user of the vehicle 105. In one example embodiment, the occupant interface subsystems 148 may be configured to wirelessly communicate with one or more devices directly or via a communication network. For example, a wireless communication system could use 3G cellular communication, such as CDMA, EVDO, GSM/GPRS, or 4G cellular communication, such as WiMAX or LTE. Alternatively, the wireless communication system may communicate with a wireless local area network (WLAN), for example, using WIFI®. In some embodiments, the wireless communication system 146 may communicate directly with a device, for example, using an infrared link, BLUETOOTH®, or ZIGBEE®. Other wireless protocols, such as various vehicular communication systems, are possible within the context of the disclosure. For example, the wireless communication system may include one or more dedicated short range communications (DSRC) devices that may include public or private data communications between vehicles and/or roadside stations.

Many or all of the functions of the vehicle 105 can be controlled by the computing system 170. The computing system 170 may include at least one data processor 171 (which can include at least one microprocessor) that executes processing instructions stored in a non-transitory computer readable medium, such as the data storage device 172. The computing system 170 may also represent a plurality of computing devices that may serve to control individual components or subsystems of the vehicle 105 in a distributed fashion. In some embodiments, the data storage device 172 may contain processing instructions (e.g., program logic) executable by the data processor 171 to perform various functions of the vehicle 105, including those described herein in connection with the drawings. The data storage device 172 may contain additional instructions as well, including instructions to transmit data to, receive data from, interact with, or control one or more of the vehicle drive subsystem 142, the vehicle sensor subsystem 144, the vehicle control subsystem 146, and the occupant interface subsystems 148.

In addition to the processing instructions, the data storage device 172 may store data such as image processing parameters, training data, roadway maps, and path information, among other information. Such information may be used by the vehicle 105 and the computing system 170 during the operation of the vehicle 105 in the autonomous, semi-autonomous, and/or manual modes.

The vehicle 105 may include a user interface for providing information to or receiving input from a user or occupant of the vehicle 105. The user interface may control or enable control of the content and the layout of interactive images that may be displayed on a display device. Further, the user interface may include one or more input/output devices within the set of occupant interface subsystems 148, such as the display device, the speakers, the microphones, or a wireless communication system.

The computing system 170 may control the function of the vehicle 105 based on inputs received from various vehicle subsystems (e.g., the vehicle drive subsystem 142, the vehicle sensor subsystem 144, and the vehicle control subsystem 146), as well as from the occupant interface subsystem 148. For example, the computing system 170 may use input from the vehicle control system 146 in order to control the steering unit to avoid an obstacle detected by the vehicle sensor subsystem 144 and the image processing module 200, move in a controlled manner, or follow a path or trajectory based on output generated by the image processing module 200. In an example embodiment, the computing system 170 can be operable to provide control over many aspects of the vehicle 105 and its subsystems.

Although FIG. 1 shows various components of vehicle 105, e.g., vehicle subsystems 140, computing system 170, data storage device 172, and image processing module 200, as being integrated into the vehicle 105, one or more of these components could be mounted or associated separately from the vehicle 105. For example, data storage device 172 could, in part or in full, exist separate from the vehicle 105. Thus, the vehicle 105 could be provided in the form of device elements that may be located separately or together. The device elements that make up vehicle 105 could be communicatively coupled together in a wired or wireless fashion.

Additionally, other data and/or content (denoted herein as ancillary data) can be obtained from local and/or remote sources by the in-vehicle control system 150 as described above. The ancillary data can be used to augment, modify, or train the operation of the image processing module 200 based on a variety of factors including, the context in which the user is operating the vehicle (e.g., the location of the vehicle, the specified destination, direction of travel, speed, the time of day, the status of the vehicle, etc.), and a variety of other data obtainable from the variety of sources, local and remote, as described herein.

In a particular embodiment, the in-vehicle control system 150 and the image processing module 200 can be implemented as in-vehicle components of vehicle 105. In various example embodiments, the in-vehicle control system 150 and the image processing module 200 in data communication therewith can be implemented as integrated components or as separate components. In an example embodiment, the software components of the in-vehicle control system 150 and/or the image processing module 200 can be dynamically upgraded, modified, and/or augmented by use of the data connection with the mobile devices 132 and/or the network resources 122 via network 120. The in-vehicle control system 150 can periodically query a mobile device 132 or a network resource 122 for updates or updates can be pushed to the in-vehicle control system 150.

System and Method for Vehicle Occlusion Detection

A system and method for vehicle occlusion detection is disclosed. The example system and method for detecting vehicle occlusion includes an offline (training) model to receive images from a camera configured on a host vehicle; generate ground truth information; train a first classifier with extracted X features for each vehicle object; track all detected vehicle objects, and train a second classifier with extracted X*N features for each vehicle object. The system and method of an example embodiment further includes an operational (non-training) model to track all detected vehicle objects to determine whether each vehicle object can be tracked back to a previous N frames or not; extract X types of features for those vehicle objects that cannot be tracked back and test with a first trained classifier; and extract X*N types of features for those vehicle objects that can be tracked back and test with a second trained classifier.

Vehicle occlusion detection is an important process for autonomous vehicle control; because, occlusion detection can provide valuable information for autonomous vehicle motion planning and driving inference generation. The various example embodiments described herein present a new method to detect the occlusion status of each vehicle captured in a static image or an image sequence. An example embodiment formulates vehicle occlusion detection as a classification problem in computer vision. In the example embodiment, for one vehicle, we classify the vehicle's occlusion status into one or more of four classes: Class 0—the vehicle occludes other vehicles, Class 1—the vehicle is occluded by other vehicles, Class 2—the vehicle is separate from other vehicles, and Class 3—the vehicle is in between two other vehicles.

In the example embodiments, two machine learning classifiers are trained and used in the vehicle occlusion detection process.

By training a first machine learning classifier for static images and a second machine learning classifier for image sequences (e.g., multiple images or dynamic images), the example embodiments disclosed herein can effectively and efficiently detect the occlusion status of each vehicle from a set of input images. Current methods are mainly trying to improve the performance of object detection and tracking by overcoming occlusion-caused challenges. However, the purpose of these current methods is totally different relative to the systems and methods described herein. In contrast to the current methods, the example embodiments described herein recognize each vehicle's four occlusion statuses to assist motion planning and driving inference generation in autonomous vehicles. In other words, conventional systems and methods fail to recognize the importance of determining and using the occlusion status of vehicle objects detected in a set of input images.

In the example embodiments described herein, supervised learning methods are used for classification of objects, object features, and object relationships captured in a set of input images. Supervised learning methods include a process of training classifiers or models using a set of training or test data in an offline training phase. By exacting predefined features and manually-annotated labels of each object (e.g., vehicle) in the input images, we can train the first machine learning classifier on many static training images. Additionally, we can train the second machine learning classifier on training image sequences. After the training phase, the trained machine learning classifiers can be used in a second phase, an operational phase, to receive real-time images and effectively and efficiently detect each vehicle's occlusion status in the received images. The training and operational use of each of the two machine learning classifiers in the example embodiment is described in more detail below.

As described in various example embodiments, a system and method for vehicle occlusion detection is disclosed. Referring now to FIG. 2, an example embodiment disclosed herein can be used in the context of an autonomous vehicle occlusion detection system 210 for autonomous vehicles. The autonomous vehicle occlusion detection system 210 can be included in or executed by the image processing module 200 as described above. The autonomous vehicle occlusion detection system 210 can include a first classifier 211 and a second classifier 212, which can correspond to the two machine learning classifiers described above. It will be apparent to those of ordinary skill in the art in view of the disclosure herein that other types of classifiers or models can be equivalently used. FIG. 2 illustrates the offline training phase (a first phase) used to configure or train the autonomous vehicle occlusion detection system 210, and the classifiers 211/212 therein, in an example embodiment based on training image data 201 and manually annotated image data 203 representing ground truth. In the example embodiment, a training image data collection system 201 can be used gather perception data to train or configure processing parameters for the autonomous vehicle occlusion detection system 210 with training image data. As described in more detail below for an example embodiment, after the initial training phase, the autonomous vehicle occlusion detection system 210 can be used in an operational or simulation phase (a second phase) to generate image feature predictions and occlusion status detections based on image data received by the autonomous vehicle occlusion detection system 210 and based on the training the autonomous vehicle occlusion detection system 210 receives during the initial offline training phase.

Referring again to FIG. 2, the training image data collection system 201 can include an array of perception information gathering devices or sensors that may include image generating devices (e.g., cameras), light amplification by stimulated emission of radiation (laser) devices, light detection and ranging (LIDAR) devices, global positioning system (GPS) devices, sound navigation and ranging (sonar) devices, radio detection and ranging (radar) devices, and the like. The perception information gathered by the information gathering devices at various traffic locations can include traffic or vehicle image data, roadway data, environmental data, distance data from LIDAR or radar devices, and other sensor information received from the information gathering devices of the data collection system 201 positioned adjacent to particular roadways (e.g., monitored locations). Additionally, the data collection system 201 can include information gathering devices installed in moving test vehicles being navigated through pre-defined routings in an environment or location of interest. Some portions of the ground truth data can also be gathered by the data collection system 201.

The image data collection system 201 can collect actual trajectories of vehicles, moving or static objects, roadway features, environmental features, and corresponding ground truth data under different scenarios. The different scenarios can correspond to different locations, different traffic patterns, different environmental conditions, and the like. The image data and other perception data and ground truth data collected by the data collection system 201 reflects truly realistic, real-world traffic information related to the locations or routings, the scenarios, and the vehicles or objects being monitored. Using the standard capabilities of well-known data collection devices, the gathered traffic and vehicle image data and other perception or sensor data can be wirelessly transferred (or otherwise transferred) to a data processor of a standard computing system, upon which the image data collection system 201 can be executed. Alternatively, the gathered traffic and vehicle image data and other perception or sensor data can be stored in a memory device at the monitored location or in the test vehicle and transferred later to the data processor of the standard computing system.

As shown in FIG. 2, a manual annotation data collection system 203 is provided to apply labels to features found in the training images collected by the data collection system 201. These training images can be analyzed by human labelers or automated processes to manually define labels or classifications for each of the features identified in the training images. The manually applied data can also include object relationship information including a status for each of the objects in a frame of the training image data, the status including a state from the group consisting of: 1) occluding another object; (2) occluded by another object; (3) there is no overlap with another object, and (4) in between two objects. As such, the manually annotated image labels and object relationship information can represent the ground truth data corresponding to the training images from the image data collection system 201. These feature labels or ground truth data can be provided to the autonomous vehicle occlusion detection system 210 as part of the offline training phase as described in more detail below.

The traffic and vehicle image data and other perception or sensor data for training, the feature label data, and the ground truth data gathered or calculated by the training image data collection system 201 and the object or feature labels produced by the manual annotation data collection system 203 can be used to generate training data, which can be processed by the autonomous vehicle occlusion detection system 210 in the offline training phase. For example, as well-known, classifiers, models, neural networks, and other machine learning systems can be trained to produce configured output based on training data provided to the classifiers, models, neural networks, or other machine learning systems in a training phase. As described in more detail below, the training data provided by the image data collection system 201 and the manual annotation data collection system 203 can be used to train the autonomous vehicle occlusion detection system 210, and the classifiers 211/212 therein, to determine the occlusion status corresponding to the objects (e.g., vehicles) identified in the training images. The offline training phase of the autonomous vehicle occlusion detection system 210 is described in more detail below.

As described above, the example embodiments can train and use two machine learning classifiers in the vehicle occlusion detection process. These two machine learning classifiers can correspond to first classifier 211 and second classifier 212, respectively. In the example embodiment, the first classifier 211 can be trained for static images and the second classifier 212 can be trained for image sequences (e.g., multiple images or dynamic images). In this manner, the classifiers 211 and 212 in combination can effectively and efficiently detect the occlusion status of each vehicle from a set of input images. The training of each of the two classifiers 211/212 in an example embodiment is described in more detail below.

Referring now to FIG. 3, a diagram illustrates a sample static image 250 that may be used by an example embodiment to train the first classifier 211 to process a static image. The static image 250 can be one of the training images provided to the autonomous vehicle occlusion detection system 210 by the training image data collection system 201 as described above. The training image data from the static image 250 can be collected and provided to the autonomous vehicle occlusion detection system 210, where the features of the static image data can be extracted. Semantic segmentation or similar processes can be used for the feature extraction. As well-known, feature extraction can provide a pixel-level object label and bounding box for each feature or object identified in the image data. In many cases, the features or objects identified in the image data will correspond to vehicle objects. As such, vehicle objects in the input static image can be extracted and represented with labels and bounding boxes. The bounding boxes can be represented as a rectangular box of a size corresponding to the extracted vehicle object. Additionally, object-level contour detections for each vehicle object can also be performed using known techniques. As a result, the autonomous vehicle occlusion detection system 210 can obtain or produce, for each received static image, vehicle object detections represented with labels and bounding boxes and object-level contour detections for each vehicle object in the static image.

Referring again to FIG. 3, the sample static image 250 illustrates a detection and extraction of three vehicle objects A, B, and C from the sample image 250. Each vehicle object is shown with a bounding box 252. In the example embodiment, the bounding box for each vehicle object can be divided into nine portions 254 of equal area (e.g., a partitioning of the vehicle bounding box with a 3×3 grid). Each bounding box for each vehicle object can be treated as an instance in the training and testing phase.

In the first training phase of the first classifier 211, the autonomous vehicle occlusion detection system 210 can partition the bounding box for each vehicle object detected in the static image into a plurality of portions. For each portion, the autonomous vehicle occlusion detection system 210 can extract the percentage of pixels in each portion that was labeled as a vehicle class in the semantic segmentation process described above. The autonomous vehicle occlusion detection system 210 can also use a related edge map for smoothing. The autonomous vehicle occlusion detection system 210 can also extract the metadata for each bounding box (e.g., a detection score, left coordinate, top coordinate, right coordinate, bottom coordinate, height, width, height*width, etc.). Additionally, the autonomous vehicle occlusion detection system 210 can extract a plurality of features for each vehicle object up to a pre-defined number of dimensions F. In an example embodiment, the feature length is defined with 35 dimensions (e.g., F=35). Given the extracted vehicle objects, the corresponding partitioned bounding boxes, the percentage of pixels in each portion labeled as a vehicle class, the object-level contour detections for each vehicle object, the edge map, the bounding box metadata, and the plurality of extracted features, the autonomous vehicle occlusion detection system 210 can determine the occlusion status for each vehicle object detected in the static input image. During the first training phase of the first classifier 211, the occlusion status for each vehicle object detected in the static input image by the autonomous vehicle occlusion detection system 210 can be compared with ground truth data corresponding to the manually generated labeling generated by the manual annotation data collection system 203. As a result, the first classifier 211 can be trained to generate occlusion status for vehicle objects in a static input image that closely correlates to ground truth data.

Referring now to FIG. 5, an operational flow diagram illustrates a process used in an example embodiment to train the first classifier 211 to generate occlusion status for vehicle objects in a static input image. Initially, the training image data from static images can be collected and provided to the autonomous vehicle occlusion detection system 210 as described above (operation block 510). As also described above, semantic segmentation or similar processes can be used for the vehicle object extraction from the static images (operation block 512) and for the feature extraction for each vehicle object in the static images (operation block 514). Given the extracted vehicle objects and the plurality of extracted features, the autonomous vehicle occlusion detection system 210 can determine the occlusion status for each vehicle object detected in the static input images (operation block 518). In a parallel or concurrent process, the manual annotation data collection system 203 can be used in operation block 516 to manually apply labels to features found in the static training images collected by the data collection system 201 and provided to the autonomous vehicle occlusion detection system 210. These training images can be analyzed by human labelers or automated processes to manually define labels or classifications for each of the features identified in the training images. As such, the manually annotated image labels and object relationship information can represent the ground truth data corresponding to the training images from the image data collection system 201. During the first training phase of the first classifier 211, the occlusion status for each vehicle object detected in the static input images by the autonomous vehicle occlusion detection system 210 can be compared with ground truth data corresponding to the manually generated labeling generated by the manual annotation data collection system 203 in operation block 516. As a result, the first classifier 211 can be trained to generate occlusion status for vehicle objects in a static input image that closely correlates to ground truth data (operation block 518).

Referring now to FIG. 4, a diagram illustrates a sample image sequence that may be used by an example embodiment to train the second classifier 212 to process image sequences. The image sequences 260 can be a plurality of the training images provided to the autonomous vehicle occlusion detection system 210 by the training image data collection system 201 as described above. The training image data from the image sequences 260 can be collected and provided to the autonomous vehicle occlusion detection system 210, where the features of the image sequence data can be extracted. Semantic segmentation or similar processes can be used for the feature extraction. As well-known, feature extraction can provide a pixel-level object label and bounding box for each feature or object identified in the image data. In many cases, the features or objects identified in the image data will correspond to vehicle objects. As such, vehicles in the input image sequence can be extracted and represented with labels and bounding boxes. The bounding boxes can be represented as a rectangular box of a size corresponding to the extracted vehicle objects. Additionally, object-level contour detections for each vehicle object can also be performed using known techniques. As a result, the autonomous vehicle occlusion detection system 210 can obtain or produce, for each received image sequence, vehicle object detections represented with labels and bounding boxes and object-level contour detections for each vehicle object in the image sequence.

Referring again to FIG. 4, a sample image sequence 260 is shown to include a plurality of images or image frames 262, 264, and 266. In the example of FIG. 4, the image frames of image sequence 260 represent a sequence of images in a temporal relationship. For example, image frame 266 can represent an image associated with a current time T, image frame 264 can represent an image associated with a previous time T-1, and image frame 262 can represent an image associated with an earlier time T-2. The sample image sequence 260 illustrates a detection and extraction of four vehicle objects A, B, C, and D from the image sequence 260 over the time period T-2 to T. Each extracted vehicle object is shown with a bounding box 252 and processed in the manner described above.

Given the vehicle object detections in an image sequence, filter-based tracking methods can be used to track the presence of each vehicle object in the plurality of image frames of the image sequence over time. For example, the presence of the tracked vehicle objects might be traced back to the previous N image frames (including the current frame) of the image sequence, wherein the Nth image frame can correspond to a time T-N where the current image frame corresponds to time T. The time-serial sequence for one tracked vehicle object in the past N image frames is treated as an instance of the object in the training and testing stages of the second classifier 212. In the example shown in FIG. 4, extracted vehicle objects A, B, and C are all present in each of the image frames of the image sequence 260. As such, each of the extracted vehicle objects A, B, and C have N associated instances where N corresponds to the number of frames in which the vehicle objects are present in the image frame. As described above, the autonomous vehicle occlusion detection system 210 can extract a plurality of features for each vehicle object up to a pre-defined number of feature dimensions. Each of the N associated instances of the vehicle objects can have associated features in a plurality of feature dimensions of quantity F. In an example embodiment, the feature length or quantity of dimensions is defined with 35 feature dimensions (e.g., F=35). Because each of the N associated instances of the vehicle objects tracked across N image frames can have F associated features, each vehicle object can have an associated N*F dynamic features in an image sequence. These N*F dynamic features can be concatenated together for each vehicle object to generate a multiplicity of dynamic feature dimensions for each extracted vehicle object tracked across N image frames of an image sequence. Referring again to the example shown in FIG. 4, extracted vehicle object D is only present in one of the image frames 266 of the image sequence 260. As such, extracted vehicle object D would only have F associated features, similar to the capture of a vehicle object in a static image as described above.

Given the extracted vehicle objects from a plurality of image frames of an image sequence, semantic segmentation on each frame of the image sequence, the corresponding partitioned bounding boxes, object-level contour detections on each frame of the image sequence, and the plurality of N*F dynamic features for each extracted vehicle object, the autonomous vehicle occlusion detection system 210 can determine the occlusion status for each vehicle object detected in the image sequence. During the first training phase of the second classifier 212, the occlusion status for each vehicle object detected in the input image sequence by the autonomous vehicle occlusion detection system 210 can be compared with ground truth data corresponding to the manually generated labeling generated by the manual annotation data collection system 203. As a result, the second classifier 212 can be trained to generate occlusion status for vehicle objects in image sequences (e.g., multiple images or dynamic images), wherein the occlusion status closely correlates to ground truth data.

Referring now to FIG. 6, an operational flow diagram illustrates a process used in an example embodiment to train the second classifier 212 to generate occlusion status for vehicle objects detected in image sequences. Initially, the training image data from the image sequences can be collected and provided to the autonomous vehicle occlusion detection system 210 as described above (operation block 520). As also described above, semantic segmentation or similar processes can be used for the vehicle object extraction from the image sequences (operation block 522). Additionally, the presence of the extracted vehicle object instances in multiple image frames of the image sequence can be tracked (operation block 524). The dynamic features for each tracked vehicle object in the image sequences can be extracted (operation block 525). Given the extracted vehicle objects and the plurality of extracted dynamic features, the autonomous vehicle occlusion detection system 210 can determine the occlusion status for each vehicle object detected in the image sequences (operation block 528). In a parallel or concurrent process, the manual annotation data collection system 203 can be used in operation block 526 to manually apply labels to features found in the image sequences or dynamic training images collected by the data collection system 201 and provided to the autonomous vehicle occlusion detection system 210. The manually annotated image labels and object relationship information can represent the ground truth data corresponding to the training image sequences from the image data collection system 201. During the first training phase of the second classifier 212, the occlusion status for each vehicle object detected in the input image sequences by the autonomous vehicle occlusion detection system 210 can be compared with ground truth data corresponding to the manually generated labeling generated by the manual annotation data collection system 203 in operation block 526. As a result, the second classifier 212 can be trained to generate occlusion status for vehicle objects in image sequences that closely correlates to ground truth data (operation block 528).

At this point, the offline training process is complete and the parameters associated with each of the first and second classifiers 211/212 have been properly adjusted to cause the first and second classifiers 211/212 to produce sufficiently accurate vehicle object occlusion status corresponding to the input image data. After being trained by the offline training process as described above, the first and second classifiers 211/212 with their properly adjusted parameters can be deployed in an operational or simulation phase (a second phase) as described below in connection with FIGS. 7 and 8.

FIG. 7 illustrates a second phase for operational or simulation use of the autonomous vehicle occlusion detection system 210 in an example embodiment. As shown in FIG. 7, the autonomous vehicle occlusion detection system 210 can receive real-world image data, including static images and image sequences, from the image data collection system 205. The image data collection system 205 can include an array of perception information gathering devices, sensors, and/or image generating devices on or associated with an autonomous vehicle, similar to the perception information gathering devices of the image data collection system 201, except that image data collection system 205 collects real-world image data and not training image data. As described in more detail herein, the autonomous vehicle occlusion detection system 210 can process the input real-world image data with the plurality of trained classifiers 211/212 to produce vehicle object occlusion data 220, which can be used by other autonomous vehicle subsystems to configure or control the operation of the autonomous vehicle.

FIG. 8 illustrates a detail of the second phase for operational or simulation use of the autonomous vehicle occlusion detection system 210 in an example embodiment. Initially, the real-world image data, including static images and image sequences can be collected by the image data collection system 205 and provided to the autonomous vehicle occlusion detection system 210 as described above (operation block 530). As also described above, semantic segmentation or similar processes can be used for the vehicle object extraction from the real-world image data (operation block 532). Additionally, the presence of the extracted vehicle object instances in multiple image frames from the real-world image data can be tracked (operation block 534). As part of the vehicle object tracking, the presence of the extracted vehicle object instances can be traced back to a previous N frames relative to the current frame. Each of the extracted vehicle objects can be traced in this manner. If a particular vehicle object is present in more than one frame of the input real-world image data, operation blocks 540 and 542 shown in FIG. 8 are performed or executed. If the particular vehicle object is present in only one frame of the input real-world image data, operation blocks 550 and 552 shown in FIG. 8 are performed or executed. In operation block 540, the particular vehicle object has been traced to more than one frame of the input real-world image data. In this case, the dynamic features of the vehicle object are extracted and provided to the second classifier 212, which determines the occlusion status for the vehicle object (operation block 542) based on the dynamic features of the vehicle object. In operation block 550, the particular vehicle object has been traced to only one frame of the input real-world image data. In this case, the static features of the vehicle object are extracted and provided to the first classifier 211, which determines the occlusion status for the vehicle object (operation block 552) based on the static features of the vehicle object. Thus, in operational or simulation usage, some vehicle objects cannot be traced back to a previous N image frames by the tracking results, depending on the length of N. Therefore, in operational or simulation usage, we use the second classifier 212 to test the vehicle objects that can be tracked back N image frames. We use the first classifier 211 to test the vehicle objects that cannot be tracked back N image frames.

The autonomous vehicle occlusion detection system 210 can process the input image data with the plurality of trained classifiers to produce vehicle object occlusion data 220, which can be used by other autonomous vehicle subsystems to configure or control the operation of the autonomous vehicle. Thus, a system and method for vehicle occlusion detection for autonomous vehicle control are disclosed.

FIGS. 9 through 12 illustrate a set of sample images that highlight the basic operations performed in an example embodiment. FIG. 9 is an example raw input image. FIG. 10 is an example of the results produced by the semantic segmentation process of the example embodiment when operating on the sample raw input image of FIG. 9. As shown, different object categories detected in the raw image are labeled using different colors. FIG. 11 is an example showing the results produced by the contour detection process of an example embodiment when operating on the sample raw input image of FIG. 9. Note that some vehicle objects shown in the contour detection results occlude or are occluded by other vehicle objects. FIG. 12 illustrates a visual representation of the vehicle object occlusion data 220 showing an occlusion status for each vehicle object as generated by the autonomous vehicle occlusion detection system 210 of an example embodiment. In the example shown in FIG. 12, red numbers (outlined with squares) are the output of our system and method and green numbers (outlined with triangles) are the corresponding ground truth as reference. Note that vehicles far from the host autonomous vehicle are ignored in one embodiment of our method.

Referring now to FIG. 13, a flow diagram illustrates an example embodiment of a system and method 1000 for vehicle occlusion detection. The example embodiment can be configured for: receiving training image data from a training image data collection system (processing block 1010); obtaining ground truth data corresponding to the training image data (processing block 1020); performing a training phase to train a plurality of classifiers, a first classifier being trained for processing static images of the training image data, a second classifier being trained for processing image sequences of the training image data (processing block 1030); receiving image data from an image data collection system associated with an autonomous vehicle (processing block 1040); and performing an operational phase including performing feature extraction on the image data, determining a presence of an extracted feature instance in multiple image frames of the image data by tracing the extracted feature instance back to a previous plurality of N frames relative to a current frame, applying the first trained classifier to the extracted feature instance if the extracted feature instance cannot be determined to be present in multiple image frames of the image data, and applying the second trained classifier to the extracted feature instance if the extracted feature instance can be determined to be present in multiple image frames of the image data (processing block 1050).

As used herein and unless specified otherwise, the term “mobile device” includes any computing or communications device that can communicate with the in-vehicle control system 150 and/or the image processing module 200 described herein to obtain read or write access to data signals, messages, or content communicated via any mode of data communications. In many cases, the mobile device 130 is a handheld, portable device, such as a smart phone, mobile phone, cellular telephone, tablet computer, laptop computer, display pager, radio frequency (RF) device, infrared (IR) device, global positioning device (GPS), Personal Digital Assistants (PDA), handheld computers, wearable computer, portable game console, other mobile communication and/or computing device, or an integrated device combining one or more of the preceding devices, and the like. Additionally, the mobile device 130 can be a computing device, personal computer (PC), multiprocessor system, microprocessor-based or programmable consumer electronic device, network PC, diagnostics equipment, a system operated by a vehicle 119 manufacturer or service technician, and the like, and is not limited to portable devices. The mobile device 130 can receive and process data in any of a variety of data formats. The data format may include or be configured to operate with any programming format, protocol, or language including, but not limited to, JavaScript, C++, iOS, Android, etc.

As used herein and unless specified otherwise, the term “network resource” includes any device, system, or service that can communicate with the in-vehicle control system 150 and/or the image processing module 200 described herein to obtain read or write access to data signals, messages, or content communicated via any mode of inter-process or networked data communications. In many cases, the network resource 122 is a data network accessible computing platform, including client or server computers, websites, mobile devices, peer-to-peer (P2P) network nodes, and the like. Additionally, the network resource 122 can be a web appliance, a network router, switch, bridge, gateway, diagnostics equipment, a system operated by a vehicle 119 manufacturer or service technician, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” can also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. The network resources 122 may include any of a variety of providers or processors of network transportable digital content. Typically, the file format that is employed is Extensible Markup Language (XML), however, the various embodiments are not so limited, and other file formats may be used. For example, data formats other than Hypertext Markup Language (HTML)/XML or formats other than open/standard data formats can be supported by various embodiments. Any electronic file format, such as Portable Document Format (PDF), audio (e.g., Motion Picture Experts Group Audio Layer 3—MP3, and the like), video (e.g., MP4, and the like), and any proprietary interchange format defined by specific content sites can be supported by the various embodiments described herein.

The wide area data network 120 (also denoted the network cloud) used with the network resources 122 can be configured to couple one computing or communication device with another computing or communication device. The network may be enabled to employ any form of computer readable data or media for communicating information from one electronic device to another. The network 120 can include the Internet in addition to other wide area networks (WANs), cellular telephone networks, metro-area networks, local area networks (LANs), other packet-switched networks, circuit-switched networks, direct data connections, such as through a universal serial bus (USB) or Ethernet port, other forms of computer-readable media, or any combination thereof. The network 120 can include the Internet in addition to other wide area networks (WANs), cellular telephone networks, satellite networks, over-the-air broadcast networks, AM/FM radio networks, pager networks, UHF networks, other broadcast networks, gaming networks, WiFi networks, peer-to-peer networks, Voice Over IP (VoIP) networks, metro-area networks, local area networks (LANs), other packet-switched networks, circuit-switched networks, direct data connections, such as through a universal serial bus (USB) or Ethernet port, other forms of computer-readable media, or any combination thereof. On an interconnected set of networks, including those based on differing architectures and protocols, a router or gateway can act as a link between networks, enabling messages to be sent between computing devices on different networks. Also, communication links within networks can typically include twisted wire pair cabling, USB, Firewire, Ethernet, or coaxial cable, while communication links between networks may utilize analog or digital telephone lines, full or fractional dedicated digital lines including T1, T2, T3, and T4, Integrated Services Digital Networks (ISDNs), Digital User Lines (DSLs), wireless links including satellite links, cellular telephone links, or other communication links known to those of ordinary skill in the art. Furthermore, remote computers and other related electronic devices can be remotely connected to the network via a modem and temporary telephone link.

The network 120 may further include any of a variety of wireless sub-networks that may further overlay stand-alone ad-hoc networks, and the like, to provide an infrastructure-oriented connection. Such sub-networks may include mesh networks, Wireless LAN (WLAN) networks, cellular networks, and the like. The network may also include an autonomous system of terminals, gateways, routers, and the like connected by wireless radio links or wireless transceivers. These connectors may be configured to move freely and randomly and organize themselves arbitrarily, such that the topology of the network may change rapidly. The network 120 may further employ one or more of a plurality of standard wireless and/or cellular protocols or access technologies including those set forth herein in connection with network interface 712 and network 714 described in the figures herewith.

In a particular embodiment, a mobile device 132 and/or a network resource 122 may act as a client device enabling a user to access and use the in-vehicle control system 150 and/or the image processing module 200 to interact with one or more components of a vehicle subsystem. These client devices 132 or 122 may include virtually any computing device that is configured to send and receive information over a network, such as network 120 as described herein. Such client devices may include mobile devices, such as cellular telephones, smart phones, tablet computers, display pagers, radio frequency (RF) devices, infrared (IR) devices, global positioning devices (GPS), Personal Digital Assistants (PDAs), handheld computers, wearable computers, game consoles, integrated devices combining one or more of the preceding devices, and the like. The client devices may also include other computing devices, such as personal computers (PCs), multiprocessor systems, microprocessor-based or programmable consumer electronics, network PC's, and the like. As such, client devices may range widely in terms of capabilities and features. For example, a client device configured as a cell phone may have a numeric keypad and a few lines of monochrome LCD display on which only text may be displayed. In another example, a web-enabled client device may have a touch sensitive screen, a stylus, and a color LCD display screen in which both text and graphics may be displayed. Moreover, the web-enabled client device may include a browser application enabled to receive and to send wireless application protocol messages (WAP), and/or wired application messages, and the like. In one embodiment, the browser application is enabled to employ HyperText Markup Language (HTML), Dynamic HTML, Handheld Device Markup Language (HDML), Wireless Markup Language (WML), WMLScript, JavaScript™, EXtensible HTML (xHTML), Compact HTML (CHTML), and the like, to display and send a message with relevant information.

The client devices may also include at least one client application that is configured to receive content or messages from another computing device via a network transmission. The client application may include a capability to provide and receive textual content, graphical content, video content, audio content, alerts, messages, notifications, and the like. Moreover, the client devices may be further configured to communicate and/or receive a message, such as through a Short Message Service (SMS), direct messaging (e.g., Twitter), email, Multimedia Message Service (MMS), instant messaging (IM), internet relay chat (IRC), mIRC, Jabber, Enhanced Messaging Service (EMS), text messaging, Smart Messaging, Over the Air (OTA) messaging, or the like, between another computing device, and the like. The client devices may also include a wireless application device on which a client application is configured to enable a user of the device to send and receive information to/from network resources wirelessly via the network.

The in-vehicle control system 150 and/or the image processing module 200 can be implemented using systems that enhance the security of the execution environment, thereby improving security and reducing the possibility that the in-vehicle control system 150 and/or the image processing module 200 and the related services could be compromised by viruses or malware. For example, the in-vehicle control system 150 and/or the image processing module 200 can be implemented using a Trusted Execution Environment, which can ensure that sensitive data is stored, processed, and communicated in a secure way.

FIG. 14 shows a diagrammatic representation of a machine in the example form of a computing system 700 within which a set of instructions when executed and/or processing logic when activated may cause the machine to perform any one or more of the methodologies described and/or claimed herein. In alternative embodiments, the machine operates as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine may operate in the capacity of a server or a client machine in server-client network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), a laptop computer, a tablet computing system, a Personal Digital Assistant (PDA), a cellular telephone, a smartphone, a web appliance, a set-top box (STB), a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) or activating processing logic that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” can also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions or processing logic to perform any one or more of the methodologies described and/or claimed herein.

The example computing system 700 can include a data processor 702 (e.g., a System-on-a-Chip (SoC), general processing core, graphics core, and optionally other processing logic) and a memory 704, which can communicate with each other via a bus or other data transfer system 706. The mobile computing and/or communication system 700 may further include various input/output (I/O) devices and/or interfaces 710, such as a touchscreen display, an audio jack, a voice interface, and optionally a network interface 712. In an example embodiment, the network interface 712 can include one or more radio transceivers configured for compatibility with any one or more standard wireless and/or cellular protocols or access technologies (e.g., 2nd (2G), 2.5, 3rd (3G), 4th (4G) generation, and future generation radio access for cellular systems, Global System for Mobile communication (GSM), General Packet Radio Services (GPRS), Enhanced Data GSM Environment (EDGE), Wideband Code Division Multiple Access (WCDMA), LTE, CDMA2000, WLAN, Wireless Router (WR) mesh, and the like). Network interface 712 may also be configured for use with various other wired and/or wireless communication protocols, including TCP/IP, UDP, SIP, SMS, RTP, WAP, CDMA, TDMA, UMTS, UWB, WiFi, WiMax, Bluetooth©, IEEE 802.11x, and the like. In essence, network interface 712 may include or support virtually any wired and/or wireless communication and data processing mechanisms by which information/data may travel between a computing system 700 and another computing or communication system via network 714.

The memory 704 can represent a machine-readable medium on which is stored one or more sets of instructions, software, firmware, or other processing logic (e.g., logic 708) embodying any one or more of the methodologies or functions described and/or claimed herein. The logic 708, or a portion thereof, may also reside, completely or at least partially within the processor 702 during execution thereof by the mobile computing and/or communication system 700. As such, the memory 704 and the processor 702 may also constitute machine-readable media. The logic 708, or a portion thereof, may also be configured as processing logic or logic, at least a portion of which is partially implemented in hardware. The logic 708, or a portion thereof, may further be transmitted or received over a network 714 via the network interface 712. While the machine-readable medium of an example embodiment can be a single medium, the term “machine-readable medium” should be taken to include a single non-transitory medium or multiple non-transitory media (e.g., a centralized or distributed database, and/or associated caches and computing systems) that store the one or more sets of instructions. The term “machine-readable medium” can also be taken to include any non-transitory medium that is capable of storing, encoding or carrying a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies of the various embodiments, or that is capable of storing, encoding or carrying data structures utilized by or associated with such a set of instructions. The term “machine-readable medium” can accordingly be taken to include, but not be limited to, solid-state memories, optical media, and magnetic media.

The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. 

What is claimed is:
 1. A system comprising: a data processor; and an autonomous vehicle occlusion detection system, executable by the data processor, the autonomous vehicle occlusion detection system being configured to perform an autonomous vehicle occlusion detection operation for autonomous vehicles, the autonomous vehicle occlusion detection operation being configured to: receive image data from an image data collection system associated with an autonomous vehicle; and perform an operational phase including performing feature extraction on the image data, determine a presence of an extracted feature instance in multiple image frames of the image data by tracing the extracted feature instance back to a previous plurality of N frames relative to a current frame, apply a first trained classifier to the extracted feature instance if the extracted feature instance cannot be determined to be present in multiple image frames of the image data, and apply a second trained classifier to the extracted feature instance if the extracted feature instance can be determined to be present in multiple image frames of the image data.
 2. The system of claim 1 being further configured to receive training image data from a training image data collection system; obtain ground truth data corresponding to the training image data; and perform a training phase to train the first classifier for processing static images of the training image data, and to train the second classifier for processing image sequences of the training image data.
 3. The system of claim 2 wherein the training phase being configured to obtain ground truth data including labeling data and object relationship information for the training image data, the object relationship information including a status for each of the objects in a frame of the training image data, the status including a state from the group consisting of: 1) occluding another object; (2) occluded by another object; (3) there is no overlap with another object, and (4) in between two objects.
 4. The system of claim 1 being configured to associate a plurality of feature dimensions of quantity F with each extracted feature instance processed by the first classifier.
 5. The system of claim 1 being configured to associate a plurality of feature dimensions of quantity F*N with each extracted feature instance processed by the second classifier.
 6. The system of claim 1 being configured to apply a bounding box to extracted features of the image data, the bounding box being partitioned into a plurality of portions.
 7. The system of claim 1 being configured to generate object-level contour detections for each extracted feature of the image data.
 8. A computer-implemented vehicle occlusion detection method comprising: receiving image data from an image data collection system associated with an autonomous vehicle; and performing an operational phase using an in-vehicle data processor installed in the autonomous vehicle, the operational phase including using the in-vehicle data processor to perform feature extraction on the image data, using the in-vehicle data processor to determine a presence of an extracted feature instance in multiple image frames of the image data by tracing the extracted feature instance back to a previous plurality of N frames relative to a current frame, using the in-vehicle data processor to apply a first trained classifier to the extracted feature instance if the extracted feature instance cannot be determined to be present in multiple image frames of the image data, and using the in-vehicle data processor to apply a second trained classifier to the extracted feature instance if the extracted feature instance can be determined to be present in multiple image frames of the image data.
 9. The method of claim 8 including receiving training image data from a training image data collection system; obtaining ground truth data corresponding to the training image data; and performing a training phase to train the first classifier for processing static images of the training image data, and to train the second classifier for processing image sequences of the training image data.
 10. The method of claim 9 wherein the training phase includes obtaining ground truth data including labeling data and object relationship information for the training image data, the object relationship information including a status for each of the objects in a frame of the training image data, the status including a state from the group consisting of: 1) occluding another object; (2) occluded by another object; (3) there is no overlap with another object, and (4) in between two objects.
 11. The method of claim 8 including associating a plurality of feature dimensions of quantity F with each extracted feature instance processed by the first classifier.
 12. The method of claim 8 including associating a plurality of feature dimensions of quantity F*N with each extracted feature instance processed by the second classifier.
 13. The method of claim 8 including applying a bounding box to extracted features of the image data, the bounding box being partitioned into a plurality of portions.
 14. The method of claim 8 including generating object-level contour detections for each extracted feature of the image data.
 15. A non-transitory machine-useable storage medium embodying instructions which, when executed by a machine, cause the machine to: receive image data from an image data collection system associated with an autonomous vehicle; and perform an operational phase including performing feature extraction on the image data, determine a presence of an extracted feature instance in multiple image frames of the image data by tracing the extracted feature instance back to a previous plurality of N frames relative to a current frame, apply a first trained classifier to the extracted feature instance if the extracted feature instance cannot be determined to be present in multiple image frames of the image data, and apply a second trained classifier to the extracted feature instance if the extracted feature instance can be determined to be present in multiple image frames of the image data.
 16. The non-transitory machine-useable storage medium of claim 15 being further configured to receive training image data from a training image data collection system; obtain ground truth data corresponding to the training image data; and perform a training phase to train the first classifier for processing static images of the training image data, and to train the second classifier for processing image sequences of the training image data.
 17. The non-transitory machine-useable storage medium of claim 16 wherein the training phase being configured to obtain ground truth data including labeling data and object relationship information for the training image data, the object relationship information including a status for each of the objects in a frame of the training image data, the status including a state from the group consisting of: 1) occluding another object; (2) occluded by another object; (3) there is no overlap with another object, and (4) in between two objects.
 18. The non-transitory machine-useable storage medium of claim 15 being configured to associate a plurality of feature dimensions of quantity F with each extracted feature instance processed by the first classifier.
 19. The non-transitory machine-useable storage medium of claim 15 being configured to associate a plurality of feature dimensions of quantity F*N with each extracted feature instance processed by the second classifier.
 20. The non-transitory machine-useable storage medium of claim 15 wherein the first classifier is a static classifier and the second classifier is a temporal classifier. 